Wolbachia Innovative Strategy

There are two Wolbachia-based control strategies available:

Suppression- This involves releasing very large number of male mosquitoes carrying Wolbachia. When these males mate with the wild females, eggs laid by female mosquitoes cannot hatch. This sterilising effect is known as Cytoplasmic Incompatibility (CI). Sustained release of Wolbachia infected male mosquitoes over a period of time will eventually reduce the natural Aedes population and hence stop disease transmission. Countries such as China and Singapore used this strategy to control the Aedes population.
Replacement- This strategy necessitates releasing both male and female mosquitoes carrying Wolbachia. When these mosquitoes mate with the wild male and female mosquitoes, eggs will be laid and hatch. All the adult mosquitoes that subsequently emerge will carry Wolbachia. Dengue, Zika and chikungunya virus cannot develop in Wolbachia-infected adult mosquitoes and so these viral diseases cannot be transmitted to human. To deploy this strategy, relatively small number of Wolbachia carrying male and female mosquitoes will be released over a period of time, until about 60% of the natural population carries Wolbachia. The Wolbachia infection will eventually spread through the wild population and disease transmission will cease since viruses cannot develop in these Wolbachia infected mosquitoes. Several countries such as Australia, Indonesia etc.had used the replacement strategy. Malaysia is currently embarking on this replacement strategy.

Suppression and Replacement Event in wild mosquitoes using Wolbachia-based strategy

The Replacement Strategy in which wild Aedes population will be replaced by Aedes carrying Wolbachia

Wolbachia have been proven to block the virus replication in mosquito